Homeowners can safely handle several basic furnace care tasks between professional maintenance visits.
You can check the filter, keep supply and return vents clear, monitor thermostat performance, inspect exterior vent openings, test CO alarms, and watch for changes in how the furnace operates.
Internal gas, combustion, electrical, and component work should be left to a qualified HVAC technician.
Check Your Furnace Filter Regularly
Check the furnace filter about once a month during the heating season.
Replace it when it becomes visibly loaded or according to the filter manufacturer’s instructions. Homes with pets, renovation dust, or heavy furnace use may need more frequent filter changes.
A dirty filter restricts airflow and can affect normal furnace operation.
Keep Supply and Return Vents Clear
Your furnace needs a clear airflow path through the home.
Supply vents deliver heated air into rooms, while return grilles bring air back to the furnace. Keep both open and free from furniture, rugs, curtains, and other obstructions.
Avoid closing multiple vents in unused rooms in an attempt to save heat.
Keep the Furnace Area Clear
Do not store boxes, paper, cleaning products, or other clutter around the furnace.
Leave enough space around the equipment for airflow, visual checks, and technician access when service is needed.
When you are near the furnace, also look for new water, staining, corrosion, or visible damage around the unit.
Check Exterior Furnace Vents After Heavy Snow
Toronto and GTA winters can bring enough snow to block exterior furnace intake or exhaust openings.
After heavy snowfall or drifting snow, check accessible vent openings from outside. If loose snow is blocking them, carefully clear it with a soft brush or broom.
Do not kick the pipes, chip ice with sharp tools, or disassemble the venting.
If the opening is damaged, iced over, or difficult to clear safely, call an HVAC technician.
Use Your Thermostat to Notice Changes Early
Your thermostat can help you spot changes in furnace performance.
Pay attention if:
- your home regularly fails to reach the set temperature
- the furnace suddenly runs much longer than usual
- the system repeatedly starts and stops
- heating behaviour changes without a thermostat schedule change
Start with simple checks such as the filter and vents. If the change continues, the furnace may need professional assessment.
Pay Attention to New Noises, Smells, or Heating Changes
You do not need to diagnose furnace sounds yourself.
A persistent new noise, unusual smell, repeated cycling, weaker heating, or frequent shutdowns means the issue has moved beyond routine homeowner maintenance.
If your furnace is already malfunctioning, see Furnace Repair in Toronto.
Test Your Carbon Monoxide Alarms
Test your CO alarms according to the manufacturer’s instructions and replace batteries or expired units when required.
If a CO alarm activates, treat it as a safety issue rather than a furnace maintenance task.
For more information, see What a Professional Furnace Safety Inspection Checks.
Know When Homeowner Maintenance Ends
Filter changes, clear vents, basic cleaning, and regular observation are useful between service visits.
Internal furnace cleaning, burner and ignition work, electrical testing, gas-related work, and combustion checks should be handled by a qualified HVAC technician.
If your furnace is due for seasonal service, Mas Air Home Comfort’s licensed technicians provide the deep cleaning and calibration needed to protect your home and your budget across Toronto, Mississauga, and Vaughan.
- Furnace Maintenance & Service: +1 (855) 795-1199
- New Furnace Installation: +1 (647) 360-6623
- Online Booking: Schedule Furnace Maintenance
